1. Field of the Invention
The present invention relates to construction panels of the type commonly used for decorative facing panels and which may also be used for environmental protection panels, such as roofing and siding panels.
2. Prior Art
A variety of panels for roofing and siding are well known in the prior art, with panels of thermoplastic, metal and fiberglass being commonly used for both purposes. Such panels are often impressed with or molded to have the decorative patterns characteristic of more conventional roofing and siding materials, such as by way of example, shake and tile materials.
One type of prior art panel manufactured by Modular Fixtures Corporation of 638 W. Seventeeth St. Costa, Mesa, Calif. is that shown in U.S. Pat. No. 3,485,002. The panel of that patent specifically simulates a Spanish tile roof, and is particularly suited for fabrication from a thermoplastic, such as ABS, using vacuum forming techniques to provide a decorative low cost panel. Obviously other decorative panels simulating other types of tile, shake or other roofing materials may also be vacuum formed onto thermoplastic sheets to provide substantially limitless ornamental appearances. However, it will be noted that the panels of the foregoing patent are not provided with any interlocking mechanism at the sides thereof, thereby not providing self alignment of adjacent panels, or any means for interlocking the panels to provide coverage of the nail heads to avoid exposed nails. Further, the absence of a suitable interlocking mechanism also inhibits the sealing against moisture between adjacent panels without the use of a suitable sealing compound. Because of the nature of the panels, the line between adjacent panels may be noticeable, and even in the embodiment where overlap of the lower course by the upper course is provided, a sufficient water barrier does not result to prevent leakage during driving rain. Accordingly such panels, regardless of the particular decorative pattern formed therein, have generally been used only for decorative purposes such as the covering of mansards, and not for area coverage, e.g., roofing systems in general. Such panels, however, have the advantage of low cost, high environmental resistance (which may be provided either by the panel material itself or by suitable, easily applied coating such as paints and plastic films), and are highly resistant to damage by impact by foreign objects, environmental extremes, etc.
Fiberglass panels with various decorative characteristics have been used to simulate tile, brick and stone, with representative panels being shown in U.S. Pat. Nos. 3,217,453 and 3,621,625. Such panels are molded from fiberglass using a press process to provide panels having a generally rectangular shape, with an interlocking tongue and groove arrangement at the four edges thereof. Panels fabricated in accordance with these two patents are generally high quality panels, and are both aesthetically pleasing and functional. However, because of the molding process and the materials from which they are fabricated, they are particularly expensive, and because of both tooling and production costs, are at a competitive disadvantage to panels fabricated from lower cost materials and/or using lower cost production techniques.
Metal roofing and siding panels are generally fabricated from materials such as aluminum. One metal siding is shown in U.S. Pat. No. 2,782,888. The element of this siding system utilizes a hook-like bend at the top of each panel to receive the lower edge of the next higher panel in the siding assembly. However, the vertical seal between sidewise adjacent panels must generally be provided by a caulking compound. Other siding and/or roofing systems utilize an outward formed hook-like region along the top of each panel, with a mating inward formed hook-like region adjacent the bottom of each panel. In this manner the lower edge of each next higher course may be hooked over the upper hook on the lower course to provide a mechanical and moisture-proof interlock therebetween. Metal roofing and siding panels have certain advantages, though are limited in the environmental integrity of the vertical and horizontal interlocking devices, are highly limited in the decorative patterns which may be created thereby and are easily damaged by foreign objects because of the softness and lack of resilience of the parent material in thin-formed sheet form, and generally provide undesirable accoustic effects in rain and hail.
Other panel-like elements are shown in U.S. Pat. Nos. 1,190,081; 2,039,536; and 2,067,059, and in Canadian Pat. No. 486,348. The elements of these patents use some form of mating or interlocking on at least two opposite sides thereof, though in general are either highly limited in the decorative pattern which may be achieved thereby and/or are expensive because of the complicated production techniques which may include the required use of composite assemblies.